This is Dr. David
feet feeling like they are burning is a sign of peripheral nerve diabetic neuropathy damage to nerves in your feet.
these nerves are suppose to send signals to your brain about your body's position and help with muscle contraction and motion.
when the nerves are not working properly, you can stagger and stumble.
have you tried diabetic nerve medications like gabapentin (Neurotin) or pregabalin (Lyrica) in higher doses to see if they help?
Elavil or carbamezapine could work as well.
an MRI scan of your spine and brain with contrast would be able to see arachnoiditis inflammation of the arachnoid layer of the brain and spinal cord.
have you had an MRI scan of your brain and total spine with IV contrast?